For the first one: What your trying to do is called radio buttons, where only one button can be checked at a time. Now, if only one button can be checked at a time, it’s no different than an enumeration. So either use an enumeration, or more simply, use a number that refers to which button is checked (i.e. 2 would be button 2, 5 would be button 5, 0 would be no buttons).
You probably don’t even need that boolean but you may find another use for it!
edit: Another benefit of wrapping User Widgets is that you can now easily stylise those checkboxes so they stay uniform throughout the menus. Makes maintenance / adjustments a breeze.